Method to improve solid ink output resolution

Abstract

A method of printing with phase change ink on an ink jet printer that contains multiple levels of black gray scale ink and a clear or slightly tinted wax ink base and which is applied to the roughened surface of an adhesion promoting coating applied to a transparent substrate is disclosed. The adhesion promoting coating has a surface roughness of greater than about 0.5 micrometers and contains a binder and an inorganic particulate material.

Having thus described the invention, what is claimed is: 
     
       1. A method of printing employing a phase change ink in an ink jet printer, the printer having a print head within multiple orifices through which ink drops are ejected onto a roughened receiving surface of an adhesion promoting coating applied over a transparent substrate to form imaged areas and non-imaged areas, the ink drops having multiple levels of black, the method of comprising the steps of: a) forming at least one imaged area on the roughened receiving surface with the ink drops having multiple levels of black ranging from a lightest level of black to a darkest level of black, the imaged area being bordered by non-imaged areas;   b) covering the non-imaged areas with a clear or slightly tinted wax ink base by applying clear or slightly tinted ink drops in the non-imaged areas adjacent the imaged areas to prevent the scattering of light transmitted through the adhesion promoting coating and the transparent substrate; and   c) fusing the imaged area and the non-imaged areas to the roughened receiving surface.   
     
     
       2. The method according to claim 1 further comprising the roughened surface of the receiving surface of the adhesion promoting coating having a root mean square surface roughness of greater than about 0.5 micrometers measured in any scanning direction. 
     
     
       3. The method according to claim 2 further comprising the adhesion promoting coating being a polymer binder and inorganic silica particulate material. 
     
     
       4. The method according to claim 2 further comprising the transparent substrate being a polyester film. 
     
     
       5. The method according to claim 3, further comprising the multiple levels of black ranging from a black to a light gray. 
     
     
       6. The method according to claim 5, further comprising the lightest level of black ink drops being light gray ink drops. 
     
     
       7. The method according to claim 1, further comprising the method being direct printing onto a final receiving surface. 
     
     
       8. The method according to claim 1, further comprising the method being indirect printing onto an intermediate transfer surface and then to a final receiving surface. 
     
     
       9. A transparency for use in medical diagnostic imaging applications, comprising in combination: a) a transparent substrate;   b) an adhesion promoting coating applied to the transparent substrate, the coating having a exposed roughened surface with a root mean square surface roughness of greater than about 0.5 micrometers; and   c) imaged and non-imaged areas formed by ink jetted phase change ink onto the exposed roughened surface of the adhesion promoting coating, the imaged areas being formed from a plurality of gray scale levels of black ink and the non-imaged areas being coated with a clear or slightly tinted wax base on top of the adhesion promoting coating.   
     
     
       10. The transparency according to claim 9 further comprising the adhesion promoting coating being a polymer binder and silica inorganic particulate material. 
     
     
       11. The transparency according to claim 10 further comprising the transparent substrate being a polyester film.